WEEK 1: CLINICAL COURSE OF HIV Flashcards
HIV medicines help people with HIV live longer, healthier lives. One of the main goals of ART is to reduce a person’s viral load to an undetectable level.
What is an undetectable viral load?
An undetectable viral load means that the level of HIV in the blood is too low to be detected by a viral load test.
There are three stages of HIV infection. State them.
(1) acute HIV infection
(2) chronic HIV infection
(3) acquired immunodeficiency syndrome (AIDS).
Why is ART is very effective at preventing HIV from multiplying?
Because an HIV treatment regimen includes HIV medicines from at least two different HIV drug classes, ART is very effective at preventing HIV from multiplying.
What are the seven stages of the HIV life cycle?
1) binding: When HIV attacks a CD4 cell, the virus binds (attaches itself) to molecules on the surface of the CD4 cell: first a CD4 receptor and then either a CCR5 or CXCR4 coreceptor.
2) fusion: After HIV attaches itself to a host CD4 cell, the HIV viral envelope fuses with the CD4 cell membrane. Fusion allows HIV to enter the CD4 cell. Once inside the CD4 cell, the virus releases HIV RNA and HIV enzymes, such as reverse transcriptase and integrase.
3) reverse transcription: HIV releases and uses reverse transcriptase (an HIV enzyme) to convert its genetic material—HIV RNA—into HIV DNA. The conversion of HIV RNA to HIV DNA allows HIV to enter the CD4 cell nucleus and combine with the cell’s genetic material—cell DNA.
4) integration: Once inside the host CD4 cell nucleus, HIV releases integrase, an HIV enzyme. HIV uses integrase to insert (integrate) its viral DNA into the DNA of the host cell.
5) replication: Once HIV is integrated into the host CD4 cell DNA, the virus begins to use the machinery of the CD4 cell to create long chains of HIV proteins. The protein chains are the building blocks for more HIV.
6) assembly: During assembly, new HIV RNA and HIV proteins made by the host CD4 cell move to the surface of the cell and assemble into immature (noninfectious) HIV.
7) budding: During budding, immature (noninfectious) HIV pushes itself out of the host CD4 cell. (Noninfectious HIV can’t infect another CD4 cell.)
Once outside the CD4 cell, the new HIV releases protease, an HIV enzyme.
Protease breaks up the long protein chains in the immature virus, creating the mature (infectious) virus.
What is a latent HIV reservoir?
A latent HIV reservoir is a group of immune system cells in the body that are infected with HIV but are not actively producing new virus.
HIV attacks immune system cells in the body and uses the cells’ own machinery to make copies of itself. However, some HIV-infected immune cells go into a resting or latent state.
While in this resting state, the infected cells do not produce new virus. HIV can hide inside these cells for years, forming a latent HIV reservoir but, at any time, cells in the latent reservoir can become active again and start making more virus.
Do HIV medicines work against latent HIV reservoirs?
HIV medicines prevent HIV from multiplying, which reduces the amount of the virus in the body (called the viral load). Because the HIV-infected cells in a latent reservoir are not producing new copies of the virus, HIV medicines have no effect on them.
What is HIV testing?
HIV testing determines if a person is infected with HIV.
HIV testing can detect HIV infection, but it cannot tell how long a person has had HIV or if the person has AIDS.
Why is HIV testing important?
What should one do if they are HIV negative?
What should one do if they are positive?
Knowing your HIV status can help keep you—and others—safe.
If you are HIV negative:
A negative HIV test result shows that you do not have HIV. Continue taking steps to avoid getting HIV, such as using condoms during sex and, if you are at high risk of getting HIV, taking medicines to prevent HIV (called pre-exposure prophylaxis or PrEP). For more information, read the HIV info fact sheet on The Basics of HIV Prevention.
If you are HIV positive:
A positive HIV test result shows that you have HIV, but you can still take steps to protect your health. Begin by talking to your health care provider about antiretroviral therapy (ART). People on ART take a combination of HIV medicines every day to treat HIV infection. ART is recommended for everyone who has HIV, and people with HIV should start ART as soon as possible. ART cannot cure HIV, but HIV medicines help people with HIV live longer, healthier lives.
A main goal of ART is to reduce a person’s viral load to an undetectable level. An undetectable viral load means that the level of HIV in the blood is too low to be detected by a viral load test. People with HIV who maintain an undetectable viral load have effectively no risk of transmitting HIV to their HIV-negative partner through sex.
Who should get tested for HIV?
Age?
Everyone 13 to 64 years of age get tested for HIV at least once as part of routine health care.
As a general rule, people at higher risk for HIV should get tested each year.
Sexually active gay and bisexual men may benefit from getting tested more often, such as every 3 to 6 months.
If you are over 64 years of age and at risk, your health care provider may recommend HIV testing.
Outline factors that increase the risk of HIV infection.
Factors that increase the risk of HIV include:
*Having vaginal or anal sex with someone who is HIV positive or whose HIV status you do not know
*Injecting drugs and sharing needles, syringes, or other drug equipment with others
*Exchanging sex for money or drugs
*Having a sexually transmitted disease (STD), such as syphilis
Should pregnant women get tested for HIV?
What is perinatal transmission?
State other synonyms.
CDC recommends that all pregnant women get tested for HIV so that they can begin taking HIV medicines if they are HIV positive. Women with HIV take HIV medicines during pregnancy and childbirth to reduce the risk of perinatal transmission of HIV and to protect their own health.
When a mother with HIV passes the virus to her infant during pregnancy, labor and delivery, or breastfeeding (through breast milk).
Maternal-Child Transmission, Mother-to-Child Transmission (MTCT), Vertical Transmission
What are the types of HIV tests?
Antibody tests check for HIV antibodies in blood or oral fluid. HIV antibodies are disease-fighting proteins that the body produces in response to HIV infection. Most rapid tests and home use tests are antibody tests.
Antigen/antibody tests can detect both HIV antibodies and HIV antigens (a part of the virus) in the blood.
NATs look for HIV in the blood.
What is window period?
The window period is the time between when a person may have been exposed to HIV and when a test can accurately detect HIV infection.
HIV testing can be confidential or anonymous.
Describe the two tests.
Confidential testing means that your HIV test results will include your name and other identifying information, and the results will be included in your medical record.
HIV-positive test results will be reported to local or state health departments to be counted in statistical reports.
Health departments remove all personal information (including names and addresses) from HIV test results before sharing the information with CDC.
CDC uses this information for reporting purposes and does not share this information with any other organizations, including insurance companies.
Anonymous testing means you do not have to give your name when you take an HIV test. When you take the test, you receive a number. To get your HIV test results, you give the number instead of your name.
What is ART?
ART is recommended for everyone with HIV, and people with HIV should start ART as soon as possible.
How is the treatment offered?
Treatment with HIV medicines is called antiretroviral therapy (ART).
People on ART take a combination of HIV medicines (called an HIV treatment regimen) every day.
A person’s initial HIV treatment regimen generally includes three HIV medicines from at least two different HIV drug classes.
What is an investigational HIV drug?
An investigational HIV drug is an experimental drug that is being studied to see whether it is safe and effective.
What are the 5 types of investigational HIV drugs are being studied?
Some types of investigational HIV drugs being studied include:
*Microbicides: A drug, chemical, or other substance used to kill microorganisms. The term is used specifically for substances that prevent or reduce the transmission of sexually transmitted diseases, such as HIV.
*Immune modulators: Immune modulators are a class of drugs that help to activate, boost, or restore normal immune function after HIV has damaged the immune system.
*Latency-reversing agents: Latency-reversing agents reactivate latent HIV within CD4 cells, allowing ART and the body’s immune system to attack the virus.
*gp120 attachment inhibitors: Attachment inhibitors are a class of antiretroviral (ARV) drugs that interfere with the early interaction between the gp120 protein on the outer surface of HIV and the CD4 receptor on the host cell (CD4 T lymphocytes [CD4 cells]). This prevents HIV from binding to and entering CD4 cells. Attachment inhibitors are part of a larger class of HIV drugs called entry inhibitors.
*Rev inhibitors: Rev is the name of an HIV protein that helps to transport HIV’s genetic information within an infected immune cell. HIV uses the Rev protein to replicate and produce new virus. Rev inhibitors are drugs that interfere with the Rev protein’s activity to prevent HIV from multiplying in the body.
How are clinical trials of investigational drugs conducted?
Clinical trials are conducted in phases. Each phase has a different purpose and helps researchers answer different questions about the investigational drug.
Phase 1 trial: Initial testing in a small group of people (20–80) to evaluate the drug’s safety and to identify side effects.
Phase 2 trial: Testing in a larger group of people (100–300) to determine the drug’s effectiveness and to further evaluate its safety.
Phase 3 trial: Continued testing in large groups of people (1,000–3,000) to confirm the drug’s effectiveness, monitor side effects, compare it with standard or equivalent treatments, and collect information to ensure that the investigational drug can be used safely.
Phase 4 trial: Ongoing tracking that occurs after a drug is approved by the FDA for sale in the United States. The purpose of the tracking is to seek more information about the drug’s risks, benefits, and optimal use.
What is a therapeutic HIV vaccine?
A therapeutic HIV vaccine is a vaccine that is designed to improve the body’s immune response to HIV in a person who already has HIV.
How is a therapeutic HIV vaccine different from a preventive HIV vaccine?
A preventive HIV vaccine is given to people who do not have HIV, with the goal of preventing HIV infection in the future.
The vaccine teaches the person’s immune system to recognize and effectively fight HIV in case the virus ever enters the person’s body.
What is a Preventive HIV Vaccine?
A preventive HIV vaccine is given to people who do not have HIV, with the goal of preventing HIV infection in the future.
What is a clinical trial?
A clinical trial is a research study done to evaluate new medical approaches in people. HIV and AIDS clinical trials help researchers find better ways to prevent, detect, or treat HIV and AIDS.
Outline the classes of HIV medicines.
- Nucleoside Reverse Transcriptase Inhibitors (NRTIs): NRTIs block reverse transcriptase, an enzyme HIV needs to make copies of itself.
EXAMPLE: Tenofovir Disoproxil Fumarate (tenofovir DF, TDF)
- Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs): NNRTIs bind to and later alter reverse transcriptase, an enzyme HIV needs to make copies of itself.
- Protease Inhibitors (PIs): PIs block HIV protease, an enzyme HIV needs to make copies of itself.
- Fusion inhibitors block HIV from entering the CD4 T lymphocyte (CD4 cells) of the immune system.
- CCR5 Antagonists: CCR5 antagonists block CCR5 coreceptors on the surface of certain immune cells that HIV needs to enter the cells.
6.Integrase Strand Transfer Inhibitor (INSTIs): Integrase inhibitors block HIV integrase, an enzyme HIV needs to make copies of itself.
- Attachment Inhibitors: Attachment inhibitors bind to the gp120 protein on the outer surface of HIV, preventing HIV from entering CD4 cells.
- Post-Attachment Inhibitors
Post-attachment inhibitors block CD4 receptors on the surface of certain immune cells that HIV needs to enter the cells. - Capsid Inhibitors
Capsid inhibitors interfere with the HIV capsid, a protein shell that protects HIV’s genetic material and enzymes needed for replication.
What is HIV drug resistance?
Once a person gets HIV, the virus begins to multiply in the body. As HIV multiplies, it sometimes changes form (mutates). Some HIV mutations that develop while a person is taking HIV medicines can lead to drug-resistant HIV.
Once drug resistance develops, HIV medicines that previously controlled the person’s HIV are no longer effective. In other words, the HIV medicines cannot prevent the drug-resistant HIV from multiplying. Drug resistance can cause HIV treatment to fail.
Can drug resistance HIV be transmitted?
Drug-resistant HIV can spread from person to person (called transmitted resistance). People with transmitted resistance have HIV that is resistant to one or more HIV medicines even before they start taking HIV medicines.
What is drug-resistance testing?
What is its importance?
Drug-resistance testing identifies which, if any, HIV medicines that will not be effective against a person’s HIV. Drug-resistance testing is done using a sample of blood.
People with HIV should start taking HIV medicines as soon as possible after their HIV is diagnosed. But before a person starts taking HIV medicines, drug-resistance testing is done.
Drug-resistance test results help determine which HIV medicines to include in a person’s first HIV treatment regimen.
Once HIV treatment is started, a viral load test is used to monitor whether the HIV medicines are controlling a person’s HIV. If viral load testing indicates that a person’s HIV treatment regimen is not effective, drug-resistance testing is repeated. The test results can identify whether drug resistance is the problem and, if so, can be used to select a new HIV treatment regimen.
How can a person taking HIV medicines reduce the risk of drug resistance?
Taking HIV medicines every day and exactly as prescribed (called medication adherence) reduces the risk of drug resistance. Skipping HIV medicines allows HIV to multiply, which increases the risk that the virus will mutate and produce drug-resistant HIV.
